Divorce (also known as dissolution of marriage) is the process of terminating a marriage or marital union. Divorce usually entails the canceling or reorganising of the legal duties and responsibilities of marriage, thus dissolving the bonds of matrimony between a married couple under the rule of law of the particular country or state. It can be said to be a legal dissolution of a marriage by a court or other competent body. It is the legal process of ending a marriage.

Divorce laws vary considerably around the world, but in most countries, divorce is a legal process that requires the sanction of a court or other authority, which may involve issues of distribution of property, child custody, alimony (spousal support), child visitation / access, parenting time, child support, and division of debt. In most countries, monogamy is required by law, so divorce allows each former partner to marry another person.

Divorce is different from annulment, which declares the marriage null and void, with legal separation or de jure separation (a legal process by which a married couple may formalize a de facto separation while remaining legally married) or with de facto separation (a process where the spouses informally stop cohabiting). Reasons for divorce vary, from sexual incompatibility or lack of independence for one or both spouses to a personality clash or infidelity.

The only countries that do not allow divorce are the Philippines and the Vatican City. In the Philippines, divorce for non-Muslim Filipinos is not legal unless one spouse is an undocumented immigrant and satisfies certain conditions. The Vatican City is a theocratic state ruled by the head of the Catholic Church, and does not allow for divorce. Countries that have relatively recently legalized divorce are Italy (1970), Portugal (1975, although from 1910 to 1940 it was possible both for the civil and religious marriage), Brazil (1977), Spain (1981), Argentina (1987), Paraguay (1991), Colombia (1991; from 1976 was allowed only for non-Catholics), Andorra (1995), Ireland (1996), Chile (2004) and Malta (2011).

Grounds for divorce vary widely from country to country. Marriage may be seen as a contract, a status, or a combination of these. Where it is seen as a contract, the refusal or inability of one spouse to perform the obligations stipulated in the contract may constitute a ground for divorce for the other spouse. In contrast, in some countries (such as Sweden, Finland, Australia, New Zealand), divorce is purely no fault, meaning that parties may separate of their own free will without having to prove someone is at fault for the divorce. Many jurisdictions offer both the option of a no fault divorce as well as an at fault divorce. This is the case, for example, in many states of the US, France and the Czech Republic.

Though divorce laws vary between jurisdictions, there are two basic approaches to divorce: fault based and no-fault based. However, even in some jurisdictions that do not require a party to claim fault of their partner, a court may still take into account the behavior of the parties when dividing property, debts, evaluating custody, shared care arrangements and support. In some jurisdictions, one spouse may be forced to pay the attorney's fees of another spouse.

Laws vary as to the waiting period before a divorce is effective. Also, residency requirements vary. However, issues of division of property are typically determined by the law of the jurisdiction in which the property is located.

In Europe, divorce laws differ from country to country, reflecting differing legal and cultural traditions. In some countries, particularly (but not only) in some former communist countries, divorce can be obtained only on one single general ground of "irretrievable breakdown of the marriage" (or a similar formulation). Yet, what constitutes such a "breakdown" of the marriage is interpreted very differently from jurisdiction to jurisdiction, ranging from very liberal interpretations (e.g. Netherlands) to quite restrictive ones (e.g., in Poland, there must be an "irretrievable and complete disintegration of matrimonial life", but there are many restrictions to granting a divorce). Separation constitutes a ground of divorce in some European countries (in Germany, e.g., a divorce is granted on the basis of a 1-year separation if both spouses consent, or 3-year separation if only one spouse consents). Note that "separation" does not necessarily mean separate residences – in some jurisdictions, living in the same household but leading a separate life (e.g., eating, sleeping, socializing, etc. separately) is sufficient to constitute de facto separation; this is explicitly stated, e.g., in the family laws of Latvia or the Czech Republic.